In a moment of zealousness, Pinchas earned eternal honor for himself and his family. As Rabbi Avigdor Miller, zt”l, explains, such is the power of zeal in the service of Hashem and His Torah.
“Pinchas Ben Elazar Ben Aharon the kohen turned away my wrath from upon the sons of Israel by his zeal for my sake in their midst; and I did not bring destruction upon the sons of Israel because of my jealousy. Therefore, say, behold, I give to him my covenant of peace” (25:11-2). This is a special proclamation of acclaim. Though Moshe certainly approved of Pinchas, Hashem here teaches the necessity to render public recognition to the righteous.
“And they shall justify the just, and they shall condemn the wicked” (Devarim 25:1) actually means that the just shall be held up to public view as men all should admire, and that the wicked must be held up as examples of scorn and public shame. Thus, in the rare instances when a prophetic Bat Kol was heard during the Second Sanctuary era, we find an instance (in the Gemara in Sanhedrin) when this miraculous phenomenon was used to point out the excellence of Hillel; and similarly, a Bat Kol came forth later to proclaim the excellence of Shmuel the Little (ibid.).
“Hashem encourages the meek” (Tehillim 147:6) (i.e. the righteous) “but He lowers the wicked to the ground” (ibid.). “Condemning the wicked, and justifying the righteous” (I Kings 8:32): this is a principle of all the narrations of the Scriptures concerning the righteous.
Against every good man (or good deed) there will always be detractors and opponents, or at best the people will fail to appreciate properly the worth of the righteous and their deeds. Here in these verses Hashem supplies a model of how to react to the deeds of the righteous and how highly we should admire their personalities and publicize their importance.
Pinchas is commended for being jealous (i.e. his zeal) for Hashem, and this jealousy was especially commended for being performed in their midst, meaning in open public demonstration. This quality of public open speech or action on behalf of Hashem is especially prized. Moshe became angry when he saw any infraction of Hashem’s Torah and was constantly commended by Hashem; we understand that Moshe was protecting the sons of Israel from the consequences of Hashem’s wrath.
When Moshe, during the episode of the golden calf, broke the Tablets, it was a monumental deed of jealousy for Hashem’s honor, and this prepared the way for the final pardon that was granted for that transgression. Similarly, when Abraham prayed that Sodom be spared destruction, Hashem consented if there would be ten righteous men, but the condition was made that they be righteous men in the midst of the city (Bereshis 18:26), meaning that they openly and publicly demonstrated their disapproval of the sins of the city. Just as the ketoret brings forgiveness from Hashem’s retribution, even more does public action for the honor of Hashem and His Torah bring forgiveness. This is the highest ketoret of all.
In the following verse, a covenant of priesthood is bestowed upon him and his posterity. But the covenant of peace for Pinchas himself is a separate covenant whereby he is assured of peace throughout his lifetime (Bamidbar Rabbah 25:1). Why was Pinchas granted an assurance of peace throughout his lifetime? Because he brought peace to the sons of Israel. This is twice stated: 1) He turned away My wrath from the sons of Israel and 2) he was zealous for his G-d and atoned for the sons of Israel (25:13). The second statement is added to explain the priesthood was bestowed upon him because he atoned for the sons of Israel, therefore he and his posterity shall atone for Israel as kohanim. Thus we learn that the man who is zealous for Hashem and His Torah is considered as one who brings peace to Israel and protects them against misfortune; and therefore he deserves a long life of enjoying the fruits of his deeds.
Pinchas was active even in the days of the War of the Concubine at Giveah (Shoftim 20:28). Similarly, though Eliyahu Hanavi departed from men (II Kings 2:11), he was rewarded in not having to die like other men (ibid.) because he was zealous for Hashem (I Kings 19:10); and in our tradition the deathless Eliyahu appeared to the Sages numerous times. Men such as these have brought upon Israel the assurance that our nation would continue deathless.